Analysis of birth records shows that in 2002 almost one in
four births in the United States was to an
immigrant mother, legal and illegal, the highest level in American history. The
enormous number and proportion of children from immigrant families may overwhelm
the assimilation process, making it difficult to integrate these new
second-generation Americans. At present, the U.S. government automatically gives
American citizenship to all people born in the country, even the children of
tourists and illegal aliens.1

Among the study's findings:

* In 2002, 23 percent of all births in the United States were to immigrant
mothers (legal or illegal), compared to 15 percent in 1990, 9 percent in 1980,
and 6 percent in 1970.

* Even at the peak of the last great wave of immigration in 1910, births to
immigrant mothers accounted for a slightly smaller share than today. After 1910
immigration was reduced, but current immigration continues at record levels,
thus births to immigrants will continue to increase.

* Our best estimate is that 383,000 or 42 percent of births to immigrants are to
illegal alien mothers. Births to illegals now account for nearly one out of
every 10 births in the United States.

* The large number of births to illegals shows that the longer illegal
immigration is allowed to persist, the harder the problem is to solve. Because
as U.S. citizens these children can stay permanently, their citizenship can
prevent a parent's deportation, and once adults they can sponsor their parents
for permanent residence.

* The large number of children born to illegals also shows that a "temporary"
worker program is unrealistic because it would result in hundreds of thousands
of permanent additions to the U.S. population each year, exactly what such a
program is supposed to avoid.

* Overall, immigrant mothers are much less educated than native mothers. In
2002, 39 percent of immigrant mothers lacked a high school education, compared
to 17 percent of native mothers. And immigrants now account for 41 percent of
births to mothers without a high school degree.

* The dramatic growth in births to immigrants has been accompanied by a decline
in diversity. In 1970, the top country for immigrant births -- Mexico -- accounted
for 24 percent of births to immigrants, by 2002 it was 45 percent.

* As a share of all births in the country, Mexican immigrants accounted for one
in 10 births in 2002. No single foreign country has ever accounted for such a
large share of births.

* In 2002, births to Hispanic immigrants accounted for 59 percent of all births
to immigrant mothers. No single cultural/linguistic group has ever accounted for
such a large share of births to immigrants.

* The states with the most dramatic increase in births to immigrants in the last
decade are Georgia, North Carolina, Nevada, Nebraska, Arkansas, Arizona,
Tennessee, Minnesota, Colorado, Delaware, Virginia, and Maryland

* Immigrants account for such a large percentage of births because they have
somewhat higher fertility and are more likely to be in their reproductive years
than natives. However, the difference with natives is not large enough to
significantly affect the nation's overall age structure.

* Immigrants who have arrived in the last two decades plus all of their
U.S.-born children have only reduced the average age in the United States from
37 to 36 years.

* Looking at the working age share (15 to 64) of the population also shows
little effect from immigration. With or without post-1980 immigrants and their
U.S.-born children, 66 percent of the population is of working age.

* While immigration has little effect on the nation's age structure, new
immigrants (legal and illegal) plus births to immigrants add some 2.3 million
people to the nation's population each year, making for a much larger overall
population.

Introduction
It is difficult to imagine a government program that has a more profound impact
on society than immigration. Large numbers of immigrants and their descendants
cannot help but shape the destiny of the country in which they settle. (The
terms "immigrant" and "foreign born" are used synonymously in this report.) Even
after the original immigrant dies or returns home, his children and descendants
will continue to exert a powerful influence on their new country's demographic,
political, economic, and cultural life. Examining births to immigrants is
therefore important, because it is a way of measuring the scale of immigration
and its impact on American society. This is especially true because the U.S.
government has chosen to award American citizenship to all persons born in the
United States, including those born to temporary visitors or even illegal
aliens. As citizens, it seems almost certain that the vast majority of these
children will live in America.

Why Study Immigrant Births? Public Expenditures on Children. All levels of government provide
services to children. Therefore, it is necessary to understand the effect of
immigration policy on the number of children being born in the United States in
order to better anticipate spending on services, especially public schools.
Children from immigrant families may also have needs that are different from
those of children from native families. Given the large share of births to
immigrants, how these children integrate into American society is critically
important to the future of the country. Thus a better understanding of
immigration's impact on births is necessary so that government may better meet
the needs of these children.

Assimilating the Children of Immigrants. There are now more than 30
million immigrants living in the country. It is sometimes suggested that because
immigrants are now so numerous it lowers their interaction with natives and
reduces their need to integrate fully into American society. Advocates of high
immigration often respond that immigrants account for a smaller share of the
population today than during the peak of the last great wave of immigration, yet
those immigrants integrated successfully. These advocates seem to be saying that
the relative sizes of the immigrant and native population matter, but we have
not reached the level of the last great wave, so there is little reason to
worry.

Of course, given the enormous changes in the world, it is not clear that
comparing current immigration with that of a century ago makes sense. Nor is it
clear that the very peak level of immigration, which itself was unusual in
American history, is the best point of comparison. Nonetheless, it is true that
at the very peak of the last great wave in 1910, the foreign born were a larger
share of the total population -- about 15 percent versus 12 percent today.
However, examining births to immigrants is relevant to the assimilation debate
because it is another way of measuring the scale of immigration and its impact
on American society.

Although children born to immigrants are by definition natives, the number and
share they represent of all births may have some bearing on how they assimilate.
After all, if births to immigrants comprise a very large share of all births,
then children from immigrant families may tend to interact primarily with each
other, having little contact with the children of natives. As a result, foreign
cultural norms, values, and even identities may be dominant among these
children. Of course, the fact that a very large share of children may come from
immigrant families does not necessarily prove that assimilation will be less
complete, since assimilation is a multifaceted and complex process. But the
issue of births to immigrants certainly is germane to the debate over the likely
course of assimilation.

Research on the Second Generation. The changing share of immigrant births
is important because it may help us to better understand how things are changing
for the children of immigrants. Researchers often examine the assimilation of
adults who had immigrant parents, referred to as second-generation Americans.
But the environment in which such individuals grew up may have fundamentally
changed. For example, an American born three decades age to immigrant parents
was raised in a country where only about one out of 20 U.S.-born children had a
foreign-born mother compared to one in four today. The situation for the
children of Mexican immigrants is even more striking. In 1970, 54,000 children
were born to Mexican immigrant mothers and they accounted for 1.5 percent of all
births. In 2002, 408,000 children were born to Mexican immigrant mothers,
accounting for 10.1 percent of all births. This change likely will have
significant impact on the childhood experience for these children. A person born
to immigrants 30 years ago may have grown up with relatively very little contact
with other children whose mothers came from the same country. But given the
enormous growth in numbers, a child born to an immigrant today may have a very
different sense of identity. We at least need to be aware of how things have
changed when thinking about the experiences of second-generation Americans.

Characteristics of Those Having Children. Another reason to examine
births to immigrants is that it provides some insight into the environment that
the children of immigrants are being born into. For example, data are available
on the education level of each child's mother. Education is important because it
is the single best indicator of income and overall socio-economic status.
Parental education levels are also a good predictor of how much education the
child will ultimately obtain. Thus, examining characteristics such as education
provides important clues to the life prospects of these children, and how they
may differ from those born to native mothers.

Births to Illegal Aliens. Illegal immigration is one of the most
contentious issues of our time. The debate involves many complex topics that go
well beyond the scope of this analysis. Birth data, however, can better inform
the debate over illegal immigration by providing insight into the number of
children born to illegal alien mothers each year. (How one estimates births to
illegals will be discussed at length in the next section.) The number of these
children has direct bearing on what policy options we decide to pursue in
dealing with this problem.

A large number of children born to illegals may mean, for example, that a
temporary worker program, like the one outlined by President Bush, is
unrealistic. As U.S. citizens, all children born to guestworkers would have the
right to stay permanently. Presumably most would return home if their parents
did so, but some would be placed with relatives or even family friends in the
reasonable belief that they would have better lives in America. As citizens this
would be their right. But even assuming the parents return home and take their
U.S.-born children with them, these citizen children have the right to return to
America at any time. A significant share can be expected to do so when they
reach adulthood.

Additionally, under current law, the citizenship of these children can be used
to prevent their parent's deportation. This is because immigration judges can
and do take into account the harm done to American citizens by a deportation.
Thus, if many guestworkers or illegal aliens with U.S. citizen children decide
to stay in America and fight deportation, their U.S. citizen children give them
excellent grounds to do so. It must also be remembered that once these children
are adults they have the right as citizens to sponsor their parents for
permanent residence without any numerical caps. All of these factors mean that a
"temporary" worker program would result in tens of millions of permanent
additions to the U.S. population, which is precisely what a temporary worker
program is supposed to avoid. But without a careful analysis of birth data of
the kind done here, one may not realize this.

Data and MethodologyData. The data for this study come from birth certificates registered in
all 50 states and the District of Columbia. The National Center for Health
Statistics (NCHS), which compiles the data, reports that more than 99 percent of
births occurring in this country are registered.2
This means that births to illegal aliens are also included in this data. The
1990 and 2002 public use files used for this study include all births in the
United States (over four million cases in 1990 and 2002) and are not samples.
The 1980 public use file includes 100 percent data for all but seven states,
which provided NCHS with 50 percent samples.3 The
1970 data file is a 50 percent sample (1.9 million cases) from every state. All
figures in this report are for births occurring within the 50 states and the
District of Columbia. Information about the mother's current place of residence,
race, age, and education level, as well as other information, are available in
the public use file for mothers.

In most, but not all, of its published reports the NCHS does not include births
to mothers who indicated that they reside outside of the United States. In 2002,
for example, there were 4,027,376 births in United States and all of these
records are on the public use file used for this study. NCHS published reports
generally show only 4,021,726 births for 2002. The 5,650 difference is births to
women who report that they reside outside of the United States. While only a
tiny fraction of all births, it seems incorrect to exclude these births, since
all of these children are U.S. citizens.4 In fact,
in some cases the data show that the mother herself was born in the United
States. Therefore, this report includes all births in the United States,
including those to mothers who reside outside of the country. This means that
state or county figures reported in this study on the place of residence of the
mother will match published numbers form NCHS, but the national total for births
in the United States are very slightly higher than in NCHS published figures
because we include births to mothers who gave a foreign residence.

Immigrant Mothers. All mothers are asked about their place of birth. This
study focuses on the years 1970, 1980, 1990, and 2002. In each of those years,
99.8 percent of mothers indicated a place of birth. The 0.2 percent of the
population that do not report place of birth of mothers will be counted with
natives. Of foreign-born mothers in the public use file, only those born in
Mexico, Canada, and Cuba are reported separately. Mothers born in other
countries are simply designated as "remainder of the world." We define
foreign-born mothers as those born outside of the United States. Mothers born
within the United States or in one of its outlying territories, such as Puerto
Rico, are considered natives. In published reports, the NCHS counts individuals
born in outlying territories as being foreign born. However, in my view it makes
more sense to count these mothers as natives because they are all U.S. citizens,
and were citizens from the day they were born. It should be noted that births to
mothers from outlying U.S. territories comprise less than 1 percent of all
births in the United States. Counting those born in outlying territories as
natives is consistent with the Census Bureau definition of native/foreign born.5
As already indicated, throughout this report we use the term immigrant and
foreign-born synonymously when referring to mothers.

What About Immigrant Fathers? The natality data used in this study do not
include a question about the father's country of birth. However the Current
Population Survey (CPS) collected by the Census Bureau does ask this question,
though the sample size is relatively small and, unlike the natality data, there
is some undercount in the CPS. The March 2002 CPS shows that for children born
in the United States in the year prior to the survey, 84 percent who had a
foreign-born mother also had a foreign-born father. Among Hispanic immigrants it
was 88 percent. If adjusted for undercount, it seems likely that 86 percent of
children born to immigrant mothers also have immigrant fathers. A similar
percentage of children with an immigrant father have an immigrant mother in the
CPS.

Estimating Births to Illegal Aliens. As already indicated, more than 99
percent of births in the United States are recorded. Thus the birth data include
births to those in the country illegally. To arrive at an estimate of births to
illegals, we estimate births per thousand for various demographic categories of
immigrant women in their reproductive years. To do this we first generate a
mid-2002 estimate of the total foreign-born population so that the number of
births relative to the size of the population can be calculated.6
We then combine this estimate with the number of births from the NCHS data to
get immigrant fertility rates by age, education level (for Mexicans), and region
or country of origin. Dividing the number of births by the size of female
foreign-born population in demographic category produces birth rates. Once we
estimate birth rates by category, we then estimate the number of illegal alien
women in each category.7 To estimate the size of the
female illegal alien population of reproductive age by category we rely on prior
research and our own analysis.8 We assume that illegal aliens have the same
fertility as their legal counterparts. The available evidence indicates that the
fertility of illegal aliens does not differ significantly from their legal
counterparts with the same characteristics.9

Our best estimates indicate that there were 383,000 births to illegal alien
mothers in 2002, accounting for 42 percent of all births to immigrants and 9.5
percent of all births in the country. While this may seem like a surprisingly
large share of births, it must be remembered that our own research, as well as
work by the Urban Institute, Pew Hispanic Center, and the Census Bureau,
indicates that more than one-fourth of the nation's immigrant population is
illegal. Moreover, because illegals come mainly to work, they are overwhelmingly
in their primary reproductive years, comprising more than one-third of all
immigrants age 18 to 39. Illegals tend to either gain legal status as they grow
older or eventually return to their home countries. Therefore, the illegal
population tends to be comprised of individuals in their 20s and 30s. In
contrast, there are a larger number of older legal immigrants who have lived in
the country for a long time and are over age 40. In addition, all prior research
indicates that 80 percent or more of illegal immigrants are Hispanic, a group
with relatively high fertility. For these reasons, illegal immigrants account
for a much larger share of births than their share in the overall population or
the immigrant population.

Birth to Immigrants Nationally
Number of Births to Immigrants. Figure 1 reports the number of births to foreign
born mothers between 1970 and 2002. The figure shows dramatic growth in births
to this population. The number of births to immigrants has grown from about
230,000 in 1970 to more than 900,000 in 2002, a 300-percent increase. The
dramatic growth in births to immigrant mothers is even more rapid than the very
substantial growth in the overall immigrant population. Between 1970 and 2002,
the number of immigrants in the United States increased from 9.6 million to 32.5
million -- a 237 percent increase.10 While the
overall growth in the immigrant population has been substantial, the growth in
the number of immigrants was still less than the increase in births to
immigrants.

Share of Births to Immigrants. Figure 2 shows that as a share of all
births in the United States, births to immigrants has increased dramatically in
recent years. In 1970, 6.1 percent of births were to immigrant mothers; by 2002
it was 22.7 percent. The share of all births accounted for by immigrant mothers
has increased 272 percent since 1970. To understand just how large the immigrant
share has become, consider that the 22.7 percent of all births attributable to
immigrants is more than 50 percent larger than the 14.7 percent of births that
black mothers represent. Or put a different way, in 2002 there were more births
to immigrants than all the births in 28 states plus the District of Columbia
combined.

Figure 2 also shows that over the last two decades the immigrant share of all
births has increased much more rapidly than their share of the total population.
As mentioned above immigrants increased their share of births by 272 percent,
but as a share of the total population they increased 145 percent. As a result,
the difference between their share of the total population and their share of
births has increased significantly. In 1970 immigrants accounted for 4.7 percent
of the total population and 6.1 percent of births -- a 1.4-percentage point
difference. But by 2002 they were 11.5 percent of total population and 22.7
percent of all births -- an 11.2 percentage point difference.

What Explains the Rapid Rise in Immigrant Births? There are several
factors contributing to the rise in the number of births to immigrants, and
their share of all births. First and most obvious is simply the increase in the
number of immigrants and their share of the overall population. But as we have
seen, Figure 2 also shows that relative to their share of the total population,
births to immigrants increased as well. The reason for this change is due to
both the changing fertility rates and age structures of the immigrant and native
populations. We examine those changes below by comparing Census Bureau
population counts with birth records.11

In 1970, the current wave of immigration had only just begun and a large share
of immigrants were long-time residents and, as a result, many were no longer in
their primary reproductive years. The 1970 Census shows that only 36 percent of
female immigrants were 15 to 44 years of age, much less than the 41 percent of
natives. But the 1980 Census shows that 46 percent of female immigrants were 15
to 44 years of age, almost the same as the 45 percent of native born Americans
in this age group. Fertility declined for both groups between 1970 and 1980,
from roughly 119 births per thousand among immigrant women age 15 to 44 to 98
births per thousand, and from 87 births per thousand for native women in 1970 to
66 births. But fertility differences between the two groups remained constant at
32 births per thousand. Thus the primary reason immigrants increased their share
of births relative to their share of the total population between 1970 and 1980
was an increase in the share of immigrants in their primary reproductive years.
By 1990 things had changed significantly: While 45 percent of natives were still
in their primary reproductive years, 53 percent of immigrants were in this age
group. Moreover, immigrant fertility went up to 117 births per thousand for
women 15 to 44, but remained relatively constant for natives at 67 per thousand.
Thus the increase in the share of all births that immigrants accounted for
between 1980 and 1990 was due to both an increase in immigrant fertility and an
increase in the share of immigrants who were in their child-bearing years.
However, for the time period 1990 to 2002 the situation is somewhat different.

Between 1990 and 2002 fertility for immigrants aged 15 to 44 actually fell from
117 births per thousand to 102 births. Fertility for natives also fell from 67
to 59 births per thousand. Thus the gap between immigrant and native fertility
actually narrowed somewhat after 1990. However, the share of immigrants in their
primary reproductive years continued to increase, from 53 percent in 1990 to 56
percent in 2002, while it fell for natives from 45 percent to 41 percent.
Therefore, the increase in the immigrant share of births relative to their share
of the total population between 1990 and 2002 was the result of a rise in the
percentage who were in their primary reproductive years and not a widening gap
between immigrant and native fertility. Overall, immigrants increased their
share of births from 1970 to 2002 for three reasons: First, and most obvious is
the dramatic increase in the overall size and share of the population that
immigrants represent; second, the share of immigrants who are in their primary
reproductive years increased relative to natives; third, the gap between
immigrant and native fertility widened. Though this gap narrowed after 1990, it
is still wider than it was in 1970.

Historical Comparison. Figures 1 and 2 make clear that the number of
births to immigrants and their share of all births represent a fundamental
change from the recent past. But what of the last great wave of immigration?
Many observers feel that the current situation is analogous to the early 20th
Century, when immigrants represented a very large share of the total population.
In 1910, immigrants reached 14.7 percent of the total population, after which
time the number entering was significantly reduced by WWI and restrictive
legislation in 1921 and 1924. Unfortunately, detailed administrative data on
births going back to that time period does not exist. But the 1910 Census can be
used to estimate the share of births that were to immigrants. Using the public
use file of the 1910 Census, we estimate that 21.9 percent of all births were to
immigrant mothers, somewhat less than today.12 This
estimate indicates that births to immigrants in 2002 likely accounted for a
larger share than at any time in American history. In interpreting these numbers
it is also important to realize that immigration was significantly reduced after
1910. But no such reduction seems to be in the offing today. Absent a change in
immigration policy it is very likely births to immigrants will reach 30 percent
of the total within a decade or so. Thus in a very real sense the present
situation and the immediate future are without precedent in American history. As
a nation we are headed into uncharted territory.

Characteristics of Mothers
The increase in births to immigrants described above provides only an overview
of the numbers and percentages. In this section, we will examine the
characteristics of immigrant mothers in order to better understand this social
phenomenon.

Educational Attainment of Mothers. The top portion of Table
1 shows the educational level of immigrant and native mothers.
Unfortunately, a large number of states, including many of the biggest states,
did not collect information on the education levels of new mothers in 1970. By
1980 most did ask the question, however several large immigrant-receiving states
still did not. Therefore is not possible to examine education levels of new
mothers for 1970 or 1980 at the national level. (Later in this report, we will
look at the education level of immigrant mothers for those states that collected
this information in 1980.) Data for 1990 and 2002, however, show a very large
gap in the education levels of immigrant and native mothers. In 1990, 44 percent
of immigrant mothers lacked a high school education and 38.9 percent lacked one
in 2002. In sharp contrast, only 20.2 percent of native mothers had not
completed high school in 1990 versus 16.5 percent in 2002. While the share of
each group that lacked a high school degree did decrease over this time period,
the gap between the two groups narrowed very little and remained enormous -- 22.4
percentage points in 2002. Despite a modest decline in the share of immigrant
mothers who lack a high school degree, the absolute number of births to
immigrants without a high school degree increased by 83,000 between 1990 and
2002. This is possible because the number of births to immigrants increased so
much that even though the percentage with little education decreased, the
overall number actually increased. Between 1990 and 2002, the number of births
to natives without high school degrees declined by 202,000. As a result, births
to immigrants represent a growing percentage of births to less-educated mothers.
The 356,000 births to immigrant mothers without a high school degree accounted
for 40.6 percent of all births to those without a high school degree in 2002,
compared to 27.9 percent in 1990. The immigrant share of births to dropouts is
striking -- especially compared to the 11.5 percent of the total population
immigrants represent.

Among more educated mothers, the gap seems to have actually grown somewhat wider
between immigrants and natives. In 1990, 15.1 percent and 18 percent of births
to immigrant and native mothers, respectively, were to those with at least a
four-year college degree, a 2.9-percentage point difference. In 2002 that
difference had widened to six percentage points, with 21.2 percent of immigrant
mothers and 27.2 percent of native mothers having a bachelors degree. Thus,
although there was an increase in the share of both immigrant and native mothers
with a college degree, the percentage went up more for natives and as a result
the difference between the two groups grew larger between 1990 and 2002. In
general, the data do not show much convergence between the two groups at the top
or bottom end of the education distribution. The education level of immigrant
mothers has remained quite different from that of natives, and those differences
have persisted for at least a decade.

Importance of Education. The very large share of births to immigrants
with little formal education has important implications for those children for
two reasons: First, education is the single best predictor of income for overall
socio-economic standing. Given the education level of many immigrant mothers, it
is certain that many of the children of immigrants are growing up quite poor,
and this may have a long-term impact on these children. For example, 37 percent
of young children in households headed by an immigrant with less than a high
school education live in poverty and an additional 41 percent have low incomes
(albeit above poverty).13 What's more, it is well
established that parental education, while not the only factor, is an important
determinant of children's likely educational attainment.14
With dropout rates for native-born Hispanics running about twice that of other
natives, the large number of births to immigrants with little education may mean
that this troubling trend will persist.15 This has
significant consequences for the prospects of these new second-generation
Americans because education has become so important to economic success in the
modern American economy. Of course, it is very difficult to predict how much
education these children may ultimately receive. However, given the education
levels of immigrant mothers, it is clear that a very large percentage of
children in immigrant families are growing up in circumstances that are quite
different from their native-born counterparts.

Age of Mothers. The bottom of Table 1 reports the
percentage of children born to immigrant and native mothers in their teens,
twenties, thirties, and forties. In terms of the share of mothers in different
age categories, there does not seem to be much meaningful difference between
immigrant and native mothers. A slightly larger share of native mothers are
teenagers than is the case among immigrant mothers. Of course, most immigrants
come to America after age 19, thus there are relatively few teenage immigrants.
Therefore it is not surprising that there are relatively few births to teenage
immigrants. Nonetheless, the fact that only about 8 percent of births to
immigrants are to teenagers is good news, and the overall decline in teenage
births for both groups is clearly a positive social trend.

Race and Ethnicity of Mothers. The top portion of Table 2
reports the race and ethnicity of new mothers. The 1970 data do not include
information on whether the mother is Hispanic so the data is not directly
comparable to other years. Not surprisingly, the figures show that immigrant and
native mothers tend to be from different groups. This difference has become
somewhat more pronounced over time. In 1980 almost 94 percent of native mothers
were either non-Hispanic black or white, compared to 37 percent of immigrant
mothers. By 2002, only 22 percent of immigrant mothers were non-Hispanic black
or white, compared to 87 percent of native mothers. While the percentages have
declined somewhat, native mothers remain overwhelming black or white, but those
two groups make up only 22 percent of new immigrant mothers in 2002. In
contrast, immigrant mothers tend to be overwhelmingly Asian or Hispanic. In 1980
almost 63 percent of immigrant mothers were from those two groups, compared to
less than 6 percent of native mothers. By 2002, the Asian and Hispanic share of
new mothers had risen to almost 78 percent among immigrants, but still only
represented 12 percent of native mothers. The main change among immigrants over
this time has been a decline in the share of births to non-Hispanic whites and a
rise in the share of mothers who are Hispanic.

As already indicated, the public use file of birth records does not contain
detailed information on the mother's country of birth. However, three countries
are reported separately: Mexico, Cuba, and Canada. The bottom of
Table 2 shows the share of immigrant mothers who are from those three
countries. Mexico is by far the top country for immigrant mothers. This is not
surprising, because Mexico is by far the top immigrant-sending country, both for
legal and illegal immigration. Putting aside figures for births, in 2002 nearly
30 percent of the total foreign-born population was from Mexico. Moreover,
Mexican immigrants tend to be relatively young and in their primary reproductive
years, and they tend to have the highest fertility of any major immigrant group.
For these reasons, births to Mexican immigrants account for almost 45 percent of
all births to immigrants in 2002, significantly higher than the 30 percent they
represent of the total immigrant population. The Mexican share of births to
immigrants has increased substantially: from 23.8 percent in 1970 to 35.9
percent in 1980, and 39.5 percent in 1990 to 44.5 percent in 2002. Throughout
the time period examined in Table 2, although data for other
Hispanics are limited in 1970, Mexicans have accounted for at least
three-fourths of births to Hispanic immigrants.16
Given that more than 10 million Mexican-born people now live in the United
States, both legally and illegally, Mexico will continue to account for a very
large share of births to immigrants for decades to come.

Declining Diversity Among Immigrant Mothers. In one sense, today's
immigration is more diverse than ever because people now arrive from every
corner of the world. In another sense, however, the diversity of immigrants has
declined significantly in the last two decades. As Table 2
shows, one country -- Mexico -- and one region -- Spanish-speaking Latin America
--
have come to dominate U.S. immigration during the last two decades. Putting
aside births, the decennial census as well as other Census Bureau data show that
Mexico, the top sending country in 1980, increased its share of the total
immigrant population from 16 percent in 1980, to 22 percent in 1990 and to 30
percent in 2002. The same data also show that Hispanic immigrants as a group
increased their share of the total immigrant population from 30 percent in 1980
to nearly half of all immigrants by 2002. The birth data in Table
2 show an even more pronounced decline in diversity than in the overall
immigrant population. Mexican mothers increased their share of births to
immigrants from 35.9 percent to 44.5 percent between 1980 and 2002. Hispanic
immigrants increased their share from 45.6 percent to 58.9 percent.

The enormous growth in the number of births to immigrants from Mexico and the
rest of Latin America means that the children of these immigrants will grow up
in very different circumstances than children born to these groups a generation
ago. For example, a child born to a Mexican immigrant mother in 1970 was
entering a country where 1.5 percent of all children (including births to
natives) had a Mexican immigrant mother. But that same child born in 2002 is
growing up in a country where more than 400,000, or 10.1 percent, of all
U.S.-born children his age have a Mexican immigrant mother. A similar situation
exists with Hispanic immigrants. In 1980, 150,000, or 4.1 percent, of all
children were born to Hispanic immigrants, but by 2002, 540,000 children were
born to Hispanic immigrants, and they comprised 13.4 percent of all U.S.-born
children. The opportunity to have continual contact with children from the same
background is now dramatically greater than it was 20 or 30 years ago.

It seems reasonable to assume that the declining diversity of immigrants must
have some implications for American society. The most serious potential problem
associated with declining diversity is that it may hinder the assimilation and
integration of immigrants and their children. Much larger numbers may provide
the critical mass necessary to create linguistic and spatial isolation. In
contrast, a more diverse immigrant population may increase incentives to learn
English or become familiar with American culture more generally. The English
language and American culture are the means by which diverse groups communicate
with each other and the larger society. But if one group dominates in an area,
then this could fundamentally reduce the need to Americanize. No one country has
ever accounted for such a large share of births to immigrants as do Mexican
immigrants today. Our analysis shows that at the peak of immigration in 1910,
the top country of immigrant births was the Russian Empire, which accounted for
18 percent of births to immigrants. Immigrants from Russia were extremely
heterogeneous and included some ethnic Russians as well as Poles, Ukrainians,
Jews, and immigrants from the Baltic states. Immigrants from Italy, a more
homogenous group, accounted for slightly more than 16 percent of births to
immigrant mothers. Moreover, immigrants from Russia and Italian immigrants each
accounted for less than 4 percent of all births in America in 1910. In contrast,
Mexican immigrants accounted for 10 percent of all births in 2002. The declining
diversity of immigrants along with the rapid growth in the number of immigrants
means that America is entering a new time, heretofore unknown in its history,
when one group is dominant among immigrants decade after decade. This fact is
reflected in the birth data. It is not at all clear what the outcome of this
situation will be.

Education Level by Race and Ethnicity.Table 3 shows
the education level of immigrant and native mothers by race and ethnicity. The
table shows very large differences between groups in both 1990 and 2002. As
already discussed, national data on the education level of mothers does not
exist for 1980 because several large states did not collect that information
then. In general, Hispanic immigrant mothers tend to have the lowest education
levels, while those from Asia tend to have the highest. In 1990 there was a
43.1-percentage-point difference between the share of Asian versus Hispanic
immigrant mothers who lacked a high school education. By 2002, the difference
was 48.8 percentage points. Although the share of each group that lacked a high
school degree improved, Asian immigrant mothers improved more, and as a result
the gap with Hispanics actually grew. A similar situation exists when comparing
Hispanic immigrants to all natives.

In 1990, 20.2 percent of all native mothers lacked a high school education
compared to 64.2 percent of Hispanic immigrant mothers -- a 44 percentage-point
difference. In 2002, 16.5 percent of native mothers and 58.8 percent of Hispanic
immigrant mothers lacked a high school education -- a 42.3-percentage point
difference. While the gap narrowed a little, the difference remained huge. In
fact, the actual number of children born to less-educated Hispanics actually
increased because the overall Hispanic immigrant population grew so much. In
1990, 223,000 children were born to Hispanic immigrant mothers without a high
school degree. In 2002 it was 317,000.

At the top end, the difference between all natives and Hispanic immigrant
mothers actually widened. In 1990, 18 percent of natives and 4.8 of Hispanic
immigrant mothers had at least a four-year college degree -- a 13.2
percentage-point difference. By 2002, 27.2 percent of native and 6.7 of Hispanic
immigrant mothers had a college degree -- a 20.5 percentage-point difference.
Although the share of both groups with a college degree increased, native
mothers made much more substantial gains and the gap widened significantly. This
is not the case for Asian immigrant mothers, a much larger share of whom had a
college degree in 2002 than in 1990. As a result, the gap with natives in terms
of college graduates actually become more pronounced in favor of Asian
immigrants between 1990 and 2002.

Table 3 shows that some of the largest gains in terms of
education among immigrant mothers were among black immigrants. Over this time
period, the share lacking a high school degree declined significantly, and the
share with a college degree increased a good deal. Although we cannot say for
sure from this data, the increasing education of black immigrant mothers may
reflect the increasing share of black immigrants who are skilled professionals
from Africa. In contrast, earlier waves of black immigration were almost
entirely Caribbean. Table 3 makes clear that there is great
diversity in the educational level of immigrant mothers. Immigrant mothers from
some parts of the world are more educated than natives while other groups are
much less educated than natives. But overall, immigrant mothers in 2002 were
much less educated than natives, and the difference between the two groups has
narrowed little or not at all in the last decade.

Births to Illegal Aliens. As indicated in the methodology section, we
estimate that there were 383,000 births to illegal alien mothers in 2002,
accounting for 41.9 percent of births to immigrants. Figure 3 shows the region
or country of birth for illegal alien mothers in 2002. The vast majority of
illegal mothers were from Mexico or elsewhere in Latin America. One question the
data do not answer is what share of the fathers were legal residents. We can say
that the number of illegal alien women married to American citizens (native born
or naturalized) is trivial because American citizens can sponsor their spouses
for green cards without numerical limits. But not all illegal alien mothers are
married. In addition, some of the fathers of these children might be Lawful
Permanent Residents (LPRs). In some cases, the spouses of LPRs must wait to
receive a green card because of numerical limits. Of course, this situation
would only arise if someone married an illegal alien after he had received LPR
status but before he became a citizen, which he can do after being in the
country for five years. Otherwise, when the immigrant received LPR status he
would have been able to bring his spouse with him as part of the normal legal
immigration system. It seems likely that perhaps 5 to 10 percent of children
born to illegal mothers have a legal father, but it is not easy to say for sure.
Of course, a similar situation must exist among illegal alien fathers who have a
child with a woman who is in the country legally. Birth data, however, do not
indicate if the father is foreign born.

Significance of Births to Illegals. The large number of children now
being born to illegal aliens each year is important for a number of reasons.
First, it makes clear the enormous scale of illegal immigration. Consider that
in recent years between 400,000 and 600,000 legal immigrants chose each year to
become American citizens; in 2004 it was 536,174. In comparison, births to
illegal immigrants are adding nearly 400,000 citizens. It is not inconceivable
that if illegal immigration is allowed to continue, there may come a time in the
not too distant future when births to illegal immigrants will actually add more
citizens to the United States each year than naturalizations of legal
immigrants.

Second, because all of these children are American citizens, there is a
permanence to the illegal alien problem. As U.S. citizens, these children have a
right to stay permanently, their citizenship can prevent a parent's deportation,
and once adults they can sponsor their parents for green cards. Thus even if all illegals were to go home, the consequences of tolerating illegal immigration are
very long-term. Third, births to illegals remind us that illegal aliens are not
simply workers or mere factors of production, which is how so many in the
business community tend to see them. They are human beings, who have children
and thus impact our society in a host of ways. We estimate that two-thirds of
illegal alien mothers lack a high school degree. Clearly many of the children of
illegal aliens will grow up in circumstances very different from those of
children of natives, even if their parents are given legal status. Thinking
about illegal immigration simply as a source of cheap labor misses the enormous
long-term challenges it creates for the country as we attempt to improve the
lives of millions of children born to illegal alien parents who have little
education. An additional effect of illegal immigration is the cost to taxpayers.
As American citizens, the children of illegal aliens are eligible for all social
services provided by federal, state, and local government. But even putting the
long term costs aside, the fiscal impact of just paying for the births to
illegal aliens is huge. We estimated that the cost to taxpayers of paying for
just the births to uninsured illegal alien mothers was $1.7 billion in 2002.17

State and Local Data
Number of Births to Immigrants by State.
Table 4 shows the
number of immigrant and native births by state for 1970, 1980, 1990, and 2002.
With almost no exceptions, births to immigrants increased in every state in the
last three decades. In many states the growth can only be described as
phenomenal. Nevada, Georgia, and North Carolina saw the most dramatic increases
between 1970 and 2002. In Nevada the number increased 19 times, in Georgia the
number increased 18 times and in North Carolina the increase was nearly 16
times.

Putting aside Nevada, which was a very small state in 1970, since 1980 the
number of births to immigrants has increased 11 times in Georgia almost 10 times
in North Carolina. In total, 21 states saw at least a five-fold increase in
births to immigrant mothers since 1970. In 22 other states the number more than
doubled. Even just the period from 1980 to 2002 shows spectacular growth. In
total, seven states saw at least a five-fold increase in births to immigrant
mothers between 1980 and 2002. In six other states the number grew more than
four-fold, in 11 additional states the number tripled, and in another 18 states
it more than doubled. Of course, in many states the number of native births also
increased significantly as the states' overall populations grew. But even so,
immigrants still have increased their share of births dramatically.

Percentage of Births to Immigrants by State.Table 5 reports the
percentage of all births by state that were to immigrant mothers in 1970, 1980,
1990, and 2002. Between 1970 and 2002, there were three states -- North Carolina,
Georgia, and Arkansas -- where immigrants increased their share of births at
least 10-fold. In 12 other states, immigrants increased their share of births at
least five-fold and in 21 states plus the District of Columbia the share
tripled. In Georgia, the immigrant share of births increased seven-fold, from
2.7 percent in 1980 to 19.1 percent in 2002. In North Carolina, the increase was
more than six times, increasing from 2.6 percent to almost 16.7 percent between
1980 and 2002. There were a total of eight states in which the immigrant share
of births increased at least four-fold and 11 states where it tripled after
1980. There were also 18 states and the District of Columbia where the share of
births to immigrants more than doubled. Even in states where a large percentage
of births were already to immigrant mothers in 1980, immigrants still increased
their share of births. In New York state, immigrants increased their share of
births from 17.8 percent to slightly over 34 percent. And in California the
immigrant share increased from 27.2 percent to 46.2 percent between 1980 and
2002. Tables 4 and 5 clearly show that the spectacular growth in births to
immigrants has not been confined to a few states; it is a national phenomenon.

The last column in Table 5 reports the share of each state's total population that was foreign
born in 2002. The figures for the total foreign born come from the March 2002
and 2003 Current Population Surveys (CPS) collected by the Census Bureau.
Because the data for the total foreign born is based on a survey, we have
averaged two years together to get a more accurate picture of the foreign born
share in smaller states. Comparing the immigrant share of the total state
population with the immigrant share of births produces some very interesting
results for a number of states. Nationally, immigrants were 11.5 percent of the
total population (11.6 percent when 2002 and 2003 data are averaged as in
Table 5) and 22.7
percent of births were to immigrants in 2002. This is roughly a two-to-one ratio
of births to immigrants. But, in some states the ratio is much larger. In
Georgia and North Carolina, for example, the ratio of births to immigrants
relative to their share of the total population is more than three to one. There
are several possible explanations for this situation. The large number of births
to immigrants in these states may mean that the undercount of the foreign born
in the census is quite large. The issue of undercount is very complex, and much
more detailed analyses would be needed in order to determine whether the
immigrant population actually is much bigger in some states than the CPS
indicates. Nonetheless, these results do make clear that in many states the
number of births to immigrants is much larger than their share of the total
population as shown in Census Bureau data. Simply looking at the share
immigrants represent of the total population, without understanding their impact
on births, may lead one to understate the actual impact of immigration policy on
many states or American society as a whole.

Education Level by State.
Table 6 reports the
share of immigrant and native mothers in 1980, 1990, and 2002 who lacked a high
school degree for those states that collected the data. As already discussed,
the education level of immigrant mothers is important because children of less
educated parents are much more likely to live in or near poverty. They are also
more likely to have special educational needs and to be at risk for dropping out
of school themselves. As we saw in Table 1, very large
differences exist between immigrant and native mothers in terms of the share
without a high school education. The differences in education are also very
large in most states. In 2002, there were eight states where immigrant mothers
were three times as likely as native mothers to lack a high school education and
20 states in which immigrant mothers were more than twice as likely as natives
to lack a high school education. One of the most striking things about
Table 6 is the
large number of states in which immigrant mothers actually become significantly
less educated. There were 31 states in which the share of immigrant mothers
without a high school education actually increased between 1990 and 2002. This
despite the fact that the trend among natives and immigrants nationally is for
an increasing percentage of new mothers to have completed high school.

In many of the states, the increase in the share of births to immigrant dropouts
was enormous. In Alabama, Nebraska, Arkansas, Indiana, North Carolina, Delaware,
Tennessee, South Dakota, South Carolina, Utah, Oklahoma, Iowa, Georgia, and
Kentucky the share of immigrant mothers without a high school degree increased
by more than 20 percentage points between 1990 and 2002. In contrast, the
percentage of native mothers without a high school education improved in every
state. In general, the states in which there was a deterioration in the share of
immigrant mothers without a high school degree were also the states with the
largest proportional growth in births to immigrants. Many of the states with the
largest increase in births to immigrants are places where a very large share of
new arrivals are from Latin America. As we have seen, Hispanic immigrants tend
to have the lowest level of education. Thus, in areas of new immigration, the
education level of immigrant mothers tended to fall significantly.

Immigrant Mothers as a Share of Dropouts.Table 7 shows the
share of all high-school dropout mothers who are immigrants. The table indicates
that immigrant mothers make up a very large percentage of births to mothers with
little formal education across the country. In 1980 there were just six states
in which immigrants accounted for more than 20 percent of births to dropouts.
But by 2002 there were 28 states in which immigrants accounted for more than 20
percent of births to mothers with less than a high school education. While it
may not be surprising that in states such California, Texas, and New York
immigrants account for a large share of births to women with little education,
it is very surprising to see that this is the case in states like Nebraska,
Oregon, and Washington. As
Table 6 showed, the
share of native mothers completing high school has increased in these states,
while immigrant mothers have become less educated at the same time as the number
of immigrants has grown. Immigrants now account for a very large share of births
to women who lack a high school degree. The impact of this growth on social
services and schools in these states is likely to be very significant.

Hispanic Share by State.Table 8 shows the
share of immigrant mothers who are Hispanic in each state. As we have seen in
Table 2, Hispanics account for a growing share of births to
immigrants nationally, increasing from 45.6 percent in 1980 to 58.9 percent in
2002. In 1980 Hispanic immigrants accounted for more than 40 percent of
immigrant births in only seven states, but by 2002 this was the case in 32
states plus the District of Columbia. In fact, Hispanics actually doubled their
share of births to immigrants in 21 states just since 1990. As already pointed
out, the rapid increase in the Hispanic share of births to immigrants helps to
explain why the overall education level of immigrant mothers deteriorated in
many parts of the country. As Table 3 shows, Hispanics tend to
have the lowest education levels of any immigrant group. As they increased their
share of births to immigrants in many states, the education level of immigrant
mothers declined. The rapid increase in the Hispanic share of immigrant births
also means that the diversity of immigrant mothers has declined in many areas of
the country.

Immigration at the County Level. Table 9 shows the
50 counties in the country in which births to immigrant mothers comprised the
largest share of births in 2002, as well as the percentage for 1990, 1980, and
1970. (While the public use natality data does not identify every individual
county, information for 400 other counties for 1990 and 2002 is available at
http://www.cis.org/articles/2005/back805data.xls )
Table 9 indicates
that immigrants account for an enormous share of births in many counties. In 15
counties, immigrant mothers account for more than half of all births. While
seven of these counties are in California, others are located in New Jersey,
Florida, Virginia, and Texas. The counties run the range from primarily urban
counties such as Los Angles, Calif., and Dade County, Fla., to suburban counties
like Orange County, Calif., and Fairfax County, Va. In 2002, the top 15 counties
accounted for 26 percent of all births to immigrant mothers in the United
States, but only 6 percent of all births to natives.

Table 9 also shows
that in some cases immigrants already accounted for a large share of births in
1970. In places like Los Angeles County, Dade County, and Queens, N.Y.,
immigrant mothers accounted for more than 20 percent of births in 1970. In other
places, immigrants accounted for a relatively modest share of births in 1970 or
even 1980, but the increase since then has been enormous. In Santa Clara,
Calif., immigrants increased as a share of births from 12.1 percent of births in
1970, to 21.1 percent in 1980, and to 61 percent in 2002. In Collier County,
Fla., they increased from 5.4 percent in 1970 to 48.3 percent in 2002. In
Gwinnett County, Ga., the increase was 1.3 percent in 1970 to 41.3 percent in
2002; in Middlesex, N.J., the increase was 8.7 percent in 1970 to 50.8 percent
by 2002; and in Fairfax County, immigrant mothers increased from 6.5 percent of
births in 1970 to 50.7 percent in 2002. These counties are not alone. Other
counties such as Alameda, Calif.; Dona Ana, N.M.; Dallas, Texas; Broward, Fla.;
Napa, Calif.; and Alexandria, Va. saw similar growth rates between 1980 and
2002. There are now many areas where immigrants account for a very large share
of births.

Metropolitan Areas.Table 10 shows the
nation's Consolidated Metropolitan Statistical Areas (CMSAs) in 2002. The CMSAs
are ranked based on the share of births to immigrant mothers in 2002. As
expected, traditional areas of immigrant settlement have the highest share of
births to immigrants. Half or more of births in the Miami, Los Angeles, and San
Francisco CMSAs are to immigrant mothers. In New York it is 40.4 percent, and in
Houston and Dallas more than a third of births are to immigrant mothers. It is
striking that such a large share of births are to immigrants in these CMSAs
because they cover very wide geographic areas, including inner and outer
suburbs, and even rural areas. Thus even though the New York CMSA includes
counties in New Jersey, Connecticut, and Pennsylvania, many of which are a good
distance from New York City, more than 40 percent of births in the CMSA are to
immigrants. Table 10
also shows that there is great variation in the number of births to immigrants
across the country. In such major metropolitan areas as Detroit, Philadelphia,
Milwaukee, and Cleveland, immigrant mothers account for a much smaller share of
births than they do nationally.

Estimated Births to Illegal Aliens in States
and Localities
In the methods section of the report we estimated the share of births to illegal
alien mothers in 2002. Below we apply the same methodology to state and local
data in order to estimate births to illegal aliens throughout the country. It
must be remembered that the figures are estimates based on the characteristics
of the mother. The numbers below should at least provide a good idea of the
share of births to illegal aliens in 2002 in states and some local areas.

Estimated Births to Illegal Aliens by State.Table 11 ranks the
states based on the estimated share of births to illegal-alien mothers by state.
In six states, births to illegal-alien mothers account for more than 50 percent
of births to immigrants, while in 15 states illegals were 40 percent or more of
births to immigrants; in another 12 states plus the District of Columbia,
illegal aliens comprised more than 30 percent of all births to immigrant
mothers. Even in parts of the country that are often not associated with
large-scale illegal immigration, births to illegal mothers still comprised a
significant share of births to immigrants. Almost one fourth of births to
immigrants in Ohio and Pennsylvania in 2002 were to illegal alien mothers. The
table also shows that immigrants comprise a significant share of all births in a
number of states. As already discussed, illegal-alien mothers are estimated to
account for 9.5 percent of all births in the United States in 2002.
Table 11 shows
that there were 10 states in which illegals comprised more than 9.5 percent of
all births. Whether 9.5 percent nationally or even higher percentages in some
states is a "large" number is, of course, a matter of perception. But it is
important to note that illegal aliens comprise about 3.6 percent of the nation's
total population. Thus, the fact that in California they are estimated to
account for more than one in five births and in three other states they account
for one in six births is certainly consequential. The impact of illegal
immigration on schools, hospitals, and social services generally is likely to be
very significant for these states.

Estimated Births to Illegals by County.Table 12 shows the
counties in which births to illegal immigrants are estimated to comprise the
largest share of births. (While the public use natality data do not identify
every individual county, information for 400 additional counties in addition to
those in Table 11
is available at www.cis.org/articles/2005/back805data.xls. ) In almost every county listed in
Table 12, illegal
aliens account for a third or more of births to immigrant mothers. Many of most
affected counties are in California or are counties near the Texas/Mexico
border. In terms of absolute numbers, the most births to illegal mothers can be
found in Los Angeles, where we estimate there were nearly 43,000 births to
illegal aliens in 2002, accounting for half of births to immigrant mothers and
28 percent of all births in the county. But counties away from California and
the border are impacted as well. For example, illegals are estimated to account
for roughly half of births to immigrants in such geographically diverse places
as Dallas, Texas; Yakima County, Wash.; Denver County, Colo.; and Collier
County, Fla. They also account for about one in four of all births in these four
counties. Table 12
shows that nationally there were a total of 26 counties in 2002 in which illegal
alien mothers are estimated to account for one out of every five births: 13 in
California, six in Texas, and one each in Arizona, Washington, Colorado, New
Mexico, Florida, Illinois, and New Jersey. Illegal immigration is clearly having
a very large impact on these counties.

Estimated Births to Illegals by CMSA.Table 13 shows
estimated births to illegal aliens in the nation's CMSAs. While CMSAs cover
large areas, it is still striking to see that illegals account for one-third of
births to immigrant mothers in nine CMSAs. It is also striking to see that they
account for one in seven of all births in seven CMSAs. The data also show that
areas of the country differ greatly in the share of births to illegal alien
mothers. For example, while illegals are estimated to account for nearly 25
percent of all births in the Los Angeles CMSA and 20 percent in the Houston CMSA,
they account for only about 3 percent of births in Detroit and 2 percent in
Cincinnati. Although illegal aliens continue to spread throughout the country,
our estimates of births show that many parts of the country remain relatively
unaffected by illegal immigration.

Impact on Age Structure
The data presented so far indicate that immigrants have a very large impact on
the number of births in the United States. Many advocates of high immigration
point to such data and argue that immigration fundamentally changes the nation's
age structure, and is very helpful in solving the problems of an aging society.
However, a recent study by the Center for Immigration Studies, as well as
estimates done by the Census Bureau and the Social Security Administration, show
that immigration has only a very small impact on the aging of society now and in
the future.18 While immigrants do tend to arrive
relatively young, and have higher fertility than natives, immigrants age just
like everyone else, and the differences with natives are not large enough to
fundamentally alter the nation's age structure.

Impact of Immigration on Fertility and Age Structure. The fact that
immigrants age over time, while obvious, is important because it partly explains
why immigration does not significantly change the nation's age structure. The
2000 Census showed that the average age of an immigrant was 39 years, compared
to 35 years for natives. One of the most important concerns of those worried
about the aging of the country is that there will be too few workers relative to
those who do not work. But the Census shows that in 2000, 66 percent of the
nation's population was of working age -- 15 to 64. If all the immigrants who
arrived after 1980 and all their U.S.-born children are excluded from the
Census, the share of the population that is of working age would be virtually
unchanged at 66 percent. Immigration adds to both the working-age population and
the population too young or too old to work. As a result it has little impact on
working age share.

The evidence is also clear that immigration has only a very modest impact on the
nation's fertility rate. In 2000, our research shows that the nation's total
fertility rate when immigrants are included is slightly under 2.1 children per
woman. Without immigrants it would be 2.0 children per woman. The much higher
fertility rate in the United States compared to Europe (1.4) and Japan (1.3) is
not due to the presence of immigrants. Rather, it reflects the higher fertility
of native-born American women, who continue to have significantly more children
on average than their counterparts in other industrialized democracies. Again,
immigration certainly adds to the number of births in the United States, but
since more than three-fourths of births are still to natives, it is native
fertility rates that mainly determine the overall fertility rate.

Immigration's Impact in the Future. The Census Bureau also has done
projections assuming different levels of immigration. Those projections indicate
that if net immigration was 100,000 to 200,000 annually, the working age share
(15 to 64) would be 58.7 percent in the year 2060, compared to 59.9 percent in
its middle immigration projections, which assume annual immigration of about one
million. The Census Bureau itself states that immigration is "a highly
inefficient" means for addressing a high ratio of working-age people relative to
those too young or too old to work. Even focusing on working-age people relative
to only retirees, excluding those under age 15, reveals little effect from
immigration. The Census Bureau's low immigration projections show that in 2060,
27 percent of the adult population (age 15+) would be 65 or older, compared to
26 percent in their medium immigration projections. Although it has little
effect on the share of the population that is of working age, immigration does
make for a much larger overall population and a more densely settled country.
The Census Bureau's middle immigration projections show that immigration will
add 97 million people to the U.S. population over the next 60 years.19
But its impact on the aging of society can only be described as very modest.

Social Security. Census Bureau projections are buttressed by projections
done by the Social Security Administration (SSA) which show that reducing legal
immigration by 41 percent would increase the size of the program's funding
deficit by only 2.5 percent. It is not clear that even this tiny effect exists,
because SSA assumes that legal immigrants will have earnings and resulting tax
payments as high as natives from the moment they arrive, which is contrary to a
large body of research. The reason legal immigration has such a modest impact on
Social Security is because immigrants do not arrive that much younger and their
fertility is not that much higher than natives. The argument that immigration
can have a significant impact on the aging of our society seems plausible.
Immigrants tend to arrive in America relatively young and they also tend to have
more children than natives. But an evaluation of the actual data shows that the
difference between immigrants and natives is not sufficiently large, nor are
immigrants sufficiently numerous to be of any real help in changing the nation's
age structure. While there is no doubt that immigration dramatically increases
the number of children born in the United States, Americans will simply have to
look elsewhere to deal with the challenges of an aging society.

ConclusionHistorical Comparison. The findings of this report show that America is
headed into uncharted territory when it comes to births to immigrants. Even at
the peak of the last great wave of immigration in 1910, births to immigrant
mothers accounted for a slightly smaller share than today. Perhaps most
important, after 1910 immigration was reduced by WWI and then restrictive
legislation in the 1920s. But current immigration continues at record levels,
thus births to immigrants will continue to increase, absent a change in U.S.
immigration policy. With over 900,000 children now born to immigrant mothers
each year, the stakes for the country are clearly enormous. Political scientist
Peter Skerry has pointed out that, "A virtual truism of the immigration
literature is that the real challenges to the receiving society arise not with
the relatively content first generation, who compare their situation with what
was left behind, but with the second and third generations, whose much higher
expectations reflect their upbringing in their parents' adopted home."20
In his 1979 book Birds of Passage, Michael Piore traces the labor unrest of the
great depression to the children of European immigrants. He also points out that
it was the children of blacks migrants from the south who rioted in northern
cities during the 1960s, not the immigrants themselves. This study does not
directly answer the question of whether the children of immigrants are
assimilating at a satisfactory pace. What we can say is that America has never
attempted to assimilate so many second-generation children.

Declining Diversity. The study finds that the increase in births to
immigrants has been accompanied by a significant decline in the diversity of
immigrants. One county, Mexico, and one region of the world, Latin America, have
come to dominate births to immigrants. Mexican mothers have increased their
share of immigrant births from 24 percent in 1970 to 45 percent by 2002.
Hispanic immigrants overall have increased their share of births from 46 percent
in 1980 to 59 percent in 2002. In contrast, the top sending country in 1910
accounted for only 18 percent of births to immigrants. America is entering a new
time, heretofore unknown, in which one group is dominant among immigrants.

Births to Illegal Aliens. We estimate that 383,000, or 42 percent, of
births to immigrant mothers were to illegal alien mothers in 2002. Births to
illegals now account for nearly one out of every 10 births in the United States.
The large number of births to illegals shows that the longer illegal immigration
is allowed to persist, the harder the problem will be to solve; as U.S. citizens
these children have a right to stay permanently, their citizenship can prevent a
parent's deportation, and once adults they can sponsor their parents for green
cards. The large number of children born to illegals also shows that a
"temporary" worker program is unrealistic. It would result in hundreds of
thousands of permanent additions to the U.S. population each year, exactly what
such a program is supposed to avoid. Births to illegal aliens remind us that illegals are not simply workers, but rather they are human beings who, like all
people, will have children. This fact alone means that tolerating widespread
illegal immigration has enormous long-term consequences for our country.

Impact on the Nation's Age Structure. Immigrants account for such a large
percentage of births because they have somewhat higher fertility and are more
likely to be in their reproductive years than natives. However, the differences
with natives are not large enough to significantly affect the nation's overall
age structure. The 2000 Census showed that 66 percent of the nation's population
was of working age (15 to 64). But if all the immigrants who arrived after 1980
and their U.S.-born children had not come to America, the Census shows that the
working age share would be virtually unchanged at 66 percent. Immigration adds
to both the working-age population and the population not of working age. While
it has little effect on the nation's age structure, immigration and births to
immigrants has added roughly 28 million people to the nation's population
between 1980 and 2000, making for a much more densely settled country.

The costs and benefits of immigration continue to be the subject of intense
debate. With more than 900,000 children born to immigrants each year, the
successful assimilation and incorporation of the children of immigrants has
become very important to the future of the country. But the dramatic increase in
births coupled with declining diversity may make it much more difficult to
assimilate these children.

End Notes1 The U.S. Supreme Court has never
directly decided whether the citizenship clause of the 14th Amendment of the
Constitution covers the offspring of illegal aliens and other non-permanent
residents. It also has never ruled whether Congress has the power to exclude
children born to illegal aliens and other non-permanent residents from U.S.
citizenship. The Court did rule in U.S. v Wong Kim Ark. 169 US 649, in 1898,
that the children of legal permanent residents were automatically citizens. For
a summary discussion of the issues surrounding immigrants and citizenship see
Charles Wood, "Losing Control of America's Future -- The Census, Birth Right
Citizenship, and Illegal Aliens." Harvard Journal of Law and Public Policy. Vol.
22, Pages 493-519, Spring 1999.

3 We follow the example of NCHS in its reports and
weight the data from the seven states to reflect the total number of births in
1980.

4 Although very small in number, the children of
diplomats are the one group who are not automatically granted citizenship, and
some mothers who indicate that they reside abroad are probably on diplomatic
visas. However, an analysis of the education level and country of birth for
these mothers indicates that relatively few are diplomats. Moreover, hospitals
that resister births do not ask if the mother is a diplomat, thus it is not at
all clear that the tiny number of children born to diplomats are in fact
excluded from citizenship.

5 While our definition of foreign born is close to
that used by the Census Bureau, the Bureau considers persons born in other
countries to American citizen parents as natives. Unlike Census data, however,
NCHS data do not include a question that asks respondents if they were born
abroad of American parents and therefore such persons cannot be distinguished
from others born in foreign countries.

6 The 2002 Current Population Survey (CPS) showed
32.45 million immigrants and the 2003 CPS showed 33.5 million. If the growth
rate was constant between 2002 and 2003, then the total foreign-born population
was 32.7 million in June of 2002. We adjust this number upward by 1.5 million to
account for immigrants missed by the CPS, creating a total foreign-born
population in June of 2002 of 34.1 million, or 5.4 percent higher than the
unadjusted total for March of 2002. We adjust this number assuming an 8 percent
undercount for Mexican immigrants, a 7 percent undercount for non-Mexican
Hispanics, and a 2.5 percent undercount for all others.

7 We estimated that there were 2.8 million illegal
alien women between the ages of 18 and 39 in 2002, 60 percent of whom are
Mexican. Of Mexican women in this age group, we estimate that 69 percent lacked
a high school degree. Overall, illegals 18 to 39 account for 95 percent of
births to illegal alien mothers. We also estimate a very small number of births
to illegal alien women under age 18 and over age 39.

8 Like almost all researchers in this field, we use
Census Bureau data to determine the size and characteristics of illegal
immigrants. Using the citizenship status, year of arrival in the United States,
age, country of birth, educational attainment, sex, receipt of welfare programs,
receipt of Social Security, veteran status, and marital status reported in the
Current Population Survey (CPS), we assign probabilities to each survey
respondent. Those individuals who have a cumulative probability of 1 or higher
are assumed to be illegal aliens. The probabilities are assigned so that both
the total number of illegal aliens and the characteristics of the illegal
population closely match other research in the field, particularly the estimates
developed by Jeffery Passel, formerly of the Urban Institute and now at the Pew
Hispanic Center. This method is based on some very well-established facts about
the characteristics of the illegal population. For example, it is well known
that illegals are disproportionately young, male, unmarried, under age 40, have
few years of schooling, etc. We adjust the number of illegals in the CPS up by
one million and estimate a total illegal population of 9.44 million in June of
2002. We further estimate that 30.5 percent of the illegal population were women
in their primary reproductive years (18 to 39) and that the illegal population
is 60 percent Mexican. We also estimate that 23 percent are from Latin American
countries other than Mexico and that the remainder of the world accounts for 17
percent of the total.

9 We believe that there is little difference in the
fertility of legal residents and illegal aliens, controlling for other
demographic characteristics, because survey data show a large number of births
to recently arrived immigrants from Latin America, who are overwhelming illegal.
For example, it is well established that the vast majority of Mexican immigrants
in 2000 who arrived in 1990 or later are illegal aliens. The Urban Institute has
estimated that in 2000, 80 percent of the Mexican population that arrived after
1990 were illegal aliens, while only 10 percent of the pre-1980 Mexican
immigrant population was illegal. Our analysis of the June 2000 Current
Population Survey, which is designed to measure fertility and includes a
question on year of arrival in the United States, shows that post-1990 Mexican
immigrant women age 20 to 40 have fertility rates that are similar to Mexican
women who arrived prior to 1990. If illegals had substantially different
fertility, then the fertility of these two groups should differ significantly,
but they do not.

10 These figures reflect the 1970 decennial Census
and the March 2002 Current Population Survey. Neither figure has been adjusted
for undercount.

11 Because our estimates for illegal immigrants
discussed earlier required detailed birth rates for 2002, we carry counts from
the March 2002 Current Population Survey forward to mid-1980 and adjust the
totals to reflect undercount by ethnicity. However, in our discussion of changes
in immigrant and native birth rates between 1970 and 2002 we make
straightforward comparisons with Census counts and do not adjust for undercounts
because no historical estimates of undercount of the foreign born going back to
1970 exist. Nonetheless, simple comparisons of this kind should still provide a
reasonable estimate of the changes in age structure and fertility among
immigrants and natives.

12 The 1910 Census asked respondents in what country
the child's mother was born. This is essentially the same question as birth
records, making it is possible to make a reasonable comparison between 1910 and
today.

13 Figures based on author's analysis of March 2002
Current Population Survey. Young children are those under age six, and low
income is defined as between 100 and 200 percent of the poverty threshold. For
natives the figures are very similar. It is the education level of these parents
that places their children at very high risk for being in or near poverty, not
whether the parent is foreign born.

14 Summarizing other research, a 1998 report by the
Council of Economic Advisors states, "parents' education is associated with
better health, development, and educational attainment for their children." The
report is at
www.access.gpo.gov/eop/ca/pdfs/ca.pdf

15 In 2002, 21 percent of Hispanic natives age 20 to
25 had not completed high school compared to 11 percent of other natives.
Figures based on author's analysis of March 2002 Current Population Survey.

16 The 1970 birth data do include a category for
"other western hemisphere" for foreign-born mothers. While this would include
non-Hispanic countries, primarily in the Caribbean, it is possible to use this
question to estimate the share of births to immigrants that are to Hispanics
other than Mexicans and Cubans.

17 In previous research we have estimated that 65
percent of illegal immigrants do not have health insurance. See Table 6 in
"Economy Slowed, But Immigration Didn't: The Foreign-Born Population,
2000-2004," at
www.cis.org/articles/2004/back1204.html . Therefore we estimated that there
were 249,000 births to uninsured illegal immigrant mothers in 2002. The average
cost of a birth in 2002 was about $8,000, according to National Inpatient
Sample. This comes to nearly $2 billion in costs for uninsured illegal immigrant
mothers. Research by Jack Hadley and John Holahan indicates that 87 percent of
the costs of care for the uninsured comes from government, the remainder coming
from the uninsured themselves, charity, and health care providers. Their
February 2003 article in Health Affairs, "How Much Medical Care Do The Uninsured
Use, And Who Pays For It?" can be found at,
www.healthaffairs.org . Assuming that
government pays for 87 percent of the cost of births to illegal aliens, then the
cost to taxpayers is an estimated $1.7 billion in 2002.